In machining apparatuses or processing apparatuses installed inside factories, the practice is to measure the dimensions of parts of products or semifinished products so as to control the machined state or processed state. In this sort of control, generally, a worker uses a caliper or tape measure to measure a specific object and confirm whether the measurement value is within a product reference value. Normally, the measurement value is manually input into a computer and the computer is used to confirm the product reference value and input value.
To measure dimensions in this way, there has been proposed a dimension measurement system which uses a digital caliper capable of transmitting measurement data so as to measure an object (Patent document 1 as described below). This dimension measurement system transmits the measurement value measured by the digital caliper to a control computer. The control computer then compares the stored reference value for the object with the measurement data and outputs “pass” or “fail” by voice. Further, there has been proposed a voice communication device enabling reliable conversation even in loud noise (Patent document 2 as described below).